CAUTION:I had quite a bit of trouble trying to make a request with fopen through a proxy to a secure url. I kept getting a 400 Bad Request back from the remote host. It was receiving the proxy url as the SNI host. In order to get around this I had to explicity set the SNI host to the domain I was trying to reach. It's apparently the issue outlined in this bug:

If you are making soap calls in WSDL mode , and the address of your web service includes a port different from 80 (like http://my_ip_address:8080//service.asmx?wsdl), the WSDL file is fetched correctly, but all subsequent requests are made without any port in the host field. This causes a SoapFault exception when trying to call any of the service’s methods.

You need to redefine the soapClient class and force the port in each call.

If the XML have identities with same name in different levels there is a solution. You don´t have to ever submit a raw XML (this PHP SOAP object don´t allows send a RAW XML), so you have to always translate your XML to a array, like the example below:

If you want to connect to a server that only supports SSLv2/3 and/or TLS 1.0 (no TLS 2 or 3), tell the SOAP client if you get a connection error by setting the appropriate stream context:<?php $opts = array('ssl' => array('ciphers'=>'RC4-SHA') );

In addition to the KeepAlive trick which is a "server-side" modification, on the "client side" default_socket_timeout should be increased from its default value (60) when you deal with ~slow SOAP servers.As for the KeepAlive, if creating a new separate vhost for the soap api is not possible, you can add this to your existing vhost: BrowserMatch "^PHP-SOAP" nokeepalivewhere PHP-SOAP is the agent name of your soap client, if you dont know what agent name your client use, just checkout the access.log of your apache.

To make an HTTPS call with a client certificate, you can do it this way:

1) Create a file containing both the key and the signed certificate. I did this by concatenating my (.pem) key and the certificate I've got signed from my CA (also .pem format). The file looked like this:

Please note, that if you provide values that contain illegal xml characters (ASCII codes 0-8, 11-12, 14-15 - or x0-x8, xB-xC, xE-xF in hex), php's SoapClient will do send them in request, although such request is improper because it does not meet XML 1.0 requirements.You always have to replace or remove these characters in your data before supplying them to SoapClient

This one drove me nuts... if you are connecting to a web service run on Cassini, (Visual Studio's web server) from php, you may not be able to call web service functions or load a WSDL out-of-the-box.

My set up is that I am using xampp on my windows development machine, and also using Visual Studio's built in web-server. I built a web service in visual studio. I wrote a simple PHP script, running under xampp, to access this service, so the two projects can 'talk' to each other. What I found was the WSDL was never loaded.

So I moved the WSDL local to the PHP file and accessed it directly. Still no calls. Turns out, PHP's SoapClient seems to have a problem with 'localhost' as a web service endpoint. So I hand-edited the web service endpoint URL to read 127.0.0.1 instead of localhost, and Voila! Web Service calls work: